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bun.sh/packages
Jarred Sumner 1ac2391b20 Reduce idle CPU usage in long-running processes (#21579)
### What does this PR do?

Releasing heap access causes all the heap helper threads to wake up and
lock and then unlock futexes, but it's important to do that to ensure
finalizers run quickly.

That means releasing heap access is a balance between:
 1. CPU usage
 2. Memory usage

Not releasing heap access causes benchmarks like
https://github.com/oven-sh/bun/pull/14885 to regress due to finalizers
not being called quickly enough.

Releasing heap access too often causes high idle CPU usage.

 For the following code:
 ```
 setTimeout(() => {}, 10 * 1000)
 ```

command time -v when with defaultRemainingRunsUntilSkipReleaseAccess =
0:
>
>   Involuntary context switches: 605
>

command time -v when with defaultRemainingRunsUntilSkipReleaseAccess =
5:
>
>   Involuntary context switches: 350
>

command time -v when with defaultRemainingRunsUntilSkipReleaseAccess =
10:
>
>  Involuntary context switches: 241
>

 Also comapre the #14885 benchmark with different values.

 The idea here is if you entered JS "recently", running any
 finalizers that might've been waiting to be run is a good idea.
 But if you haven't, like if the process is just waiting on I/O
 then don't bother.

### How did you verify your code works?
2025-08-03 18:14:40 -07:00
..
2025-07-10 00:10:43 -07:00
2025-07-10 00:10:43 -07:00